import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description: 判断一个数是否为素数
 * Author:  LiuTao
 * Version: 1.0
 * Date:    2023-07-30  14:53
 */
public class Test3 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = scanner.nextInt();
        int i = 0;
        for (i = 2; i < num; i++) {
            if(num % i == 0) {
                System.out.println(num + "不是素数！");
                break;
            }
        }
        if(i == num) {
            System.out.println(num + "是素数！");
        }
    }
}
